What tool or technique used by Ivanowski and Beijerinck while studying diseased tobacco plants enabled them to determine that the disease was caused by an agent significantly smaller than bacteria

Wind energy is plentiful in regions with vast open spaces it is a non polluting renewable resource what could be an economic factor that makes the use of this resource less feasible then non renewable resource even in such regions

Plz ! ive been stuck on this forever

How does the carbon cycle involve an exchange of carbon